Bonding device employing temporary magnetic attaching means

ABSTRACT

An apparatus and method for bonding a first object to the surface of a second magnetic object. Magnets on the first object attach the first object to the magnetic object, spaced therefrom by the magnets, while a special ejector system compresses an adhesive material into the space to secure the two objects together.

llnited States Patent egan, Jr. a [4 1 Apr. 1, 1972 BONDING DEVICE EMPLOYING I References Cited gqEEhgggRARY MAGNETIC ATTACHING UNHED STATES PATENTS 2,713,379 7/1955 Sisson ..269/8 [72] Inventor: Edgar P. Regan, Jr-, Fairfax, V 2,988,13l 6/1961 Frohlich et al.... ..l56/394 UX [73] Assigneez The United states of America as 3,332,820 7/1967 Porter ..l56/394 represented by the Secretary of the Navy Primary Examiner-Benjamin R. Padgett [22] Filed: Feb. 12, 1969 Assistant Examiner-Stephen J. Lechert, Jr.

Attorney-R. S. Sciascia and J. A. Cooke [21] Appl. No.: 798,673

[57] ABSTRACT [52] U.S. Cl ..l56/350, 156/391, 156/556 An apparatus and method for bonding a first object to the sur- [51] int. 'Cl ..B32b 31/00 face of a second magnetic object. Magnets on the first object [58] Field of Search ..l56/272, 275, 276, 350, 380, attach the first object to the magnetic object, spaced 156/391, 556 therefrom by the magnets, while a special ejector system compresses an adhesive material into the space to secure the two objects together.

7 Claims, 2 Drawing Figures PMENTEDAPR 181972 3, 657, 050 sum-11oF 2 "-1 g j t I" W14.

Edgar P Regan, Jr.

INVENTOR ATTOR Y AGENT BACKGROUND OF THE INVENTION This invention generally relates to attachment devices and more particularly to an apparatus and method for bonding a first object to the surface of a second ferromagnetic object.

The apparatus and method of the present invention are especially well suited for use in such areas as the underwater recovery of oceanographic or military test systems such as, for example, small research vehicles or test mines. In such rescue or recovery operations, the attachment of mechanical devices to the object being recovered presents a difficult and timeconsuming task to an underwater swimmer or rescue vehicle undertaking the rescue. With the present invention an object containing a magnetic attaching device and an adhesive ejector system may easily be positioned adjacent the object being recovered and actuated to commence an attachment between the objects that takes place automatically without further effort on the part of the swimmer or diver. Also, the present invention could easily be incorporated within the hull of a rescue vehicle for attaching the vehicle itself to the object being recovered.

Although mechanical attachment devices and other magnetic attachment devices are known and have been used previously for underwater operations of the nature described, these devices do not possess adequate holding power or attachment strength for all instances.

The present invention has been described as particularly useful in underwater operations, but it is to be understood that it works equally well outside of a water environment and, ac cordingly, may be used in any attachment application either underwater or on the surface, as desired.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an improved method and apparatus for attaching a first object to a second magnetic object.

Another object of the invention is the provision of an apparatus and method for adhesively bonding an underwater object to a second underwater, magnetic object.

The foregoing and other objects are attained by a device which provides for an initial temporary spatial attachment of the two objects by magnetic means and a final permanent attachment by an adhesive bond injected within the space between the two objects.

BRIEF DESCRIPTION OF THE DRAWING Other object and features of the invention will be come apparent to those skilled in the art as disclosure is made in the following description of a preferred embodiment of the invention as illustrated in the accompanying drawing wherein:

FIG. 1 is a sectional view of a magnetic standoff assembly and an adhesive ejector system constructed according to the teachings of this invention; and

FIG. 2 is a schematic view of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings and more particularly to FIG. 1 thereof, a pair of standoff assemblies for temporarily magnetically attaching a first object 11 such as an underwater rescue vehicle to a second metallic or ferromagnetic object 11 such as a disabled research vehicle with a predetermined gap therebetween is generally indicated at 10. Each assembly is permanently mounted upon the first object 11 and comprises a box-shaped block 12 open at one end to the outside surface of the object and having a reduced neck portion 13 at its other end. A cylindrical piston 14 is slidably disposed within a bore 15 formed in the neck portion 13 of the block 12. The piston 14 is provided with an annular groove in which there is positioned an O-ring 16 for providing a fluid seal between the piston 14 and the block 12.

A rod 17 is integrally formed with piston 14 and extends through an aperture 19 in the upper wall of block 12 and is slidable therein. The aperture 19, being coaxial with and smaller in diameter than the bore 15, forms an internal shoulder 20 between the neck 13 and the upper wall of block 12. Disposed in the bore 15 about the rod 17 and compressed between the inner face of piston 14 and the shoulder 20 is a coil spring 21, which urges the piston in a direction away from the upper wall of the block 12 and normally maintains the piston in flush contact with an end closure plug 22 for the bore 15. The end closure plug 22 is secured to the neck 13 by any suitable means such as, for example, by threaded engagement.

A horse-shoe magnet 23 is positioned within a cavity 24 formed in the block 12 and is secured to the end of the rod 17 remote from the piston 14 for movement therewith along a line coaxial with the axis of bore 15 so that, as shown, the magnet 23 may be displaced from the block 12 through an opening 25 in the wall of the object 11 to extend beyond the outer surface thereof. The magnet 23 is carried by a support 26 having a threaded pin 27 centrally formed thereon which is secured within a threaded axial bore 28 centrally formed in rod 17. Other means for attaching the magnet 23 to the rod 17 may of course be relied upon.

A channel 30 is provided in the outer surface of the rod 17 parallel to the longitudinal axis thereof for receiving a springloaded pin 31 mounted within an end wall of block 12 to prevent rotation of the magnet 23 during displacement thereof. The channel 30 extends along the length of rod 17 from the end thereof adjacent the support 26 to a point where it drops off into a deeper slot 32, the purpose of which is to provide shoulders 18 and 29 formed thereby with the rod 17 for limiting the displacement of rod 17 and magnet 23 in either direction wherever pin 31 engages slot 32 to a predetermined distance such as, for example, a distance sufiicient to extend magnet 23 beyond the surface of object 11 an amount equal to the aforementioned gap and to permit withdrawal or retraction of the magnet only to a position of flush contact with the surface of the object.

An adhesive ejector 33 for forcing an adhesive into the gap between the two objects that are to be attached is also mounted within object 11. The ejector comprises a substantially cylindrical container 34 having slidably mounted therein a piston 35 provided with an O-ring fluid seal 36. One end of the container 34 is provided with centrally disposed aperture 37 normally closed by a bladder or diaphragm 38 secured in place across the aperture by a longitudinal coupling member 39 threadably engaged with the container end wall, or secured thereto in any similar suitable conventional manner. The coupler 39 is secured to the container 34 so that an axial bore 40 formed therein is aligned with the aperture 37 of the container for ejecting therethrough an adhesive 41 from the container in a manner to be set forth hereinafter.

At the other end of the cylindrical container 34 a T-shaped closure plug 42 is threadably secured thereto. The piston 35 is provided with a circumferential flange or rib 43 that spaces the piston from the top wall of closure plug 42 and thereby provides a small cavity 44 therebetween. The cavity 44 is open to a fluid pressure line 45 for receiving fluid under pressure to actuate the piston 35. Also, a rod 46 of the piston 35 normally is positioned within the leg 47 of the T-closure 42 in slidable and sealed relation therewith. Another fluid pressure line 48 is connected into the end of the leg 47 for receiving fluid under pressure via line 45 and cavity 44 whenever the piston 35 is displaced to the point where rod 46 clears the O-ring seal 50 between itself an an annular depending ring of the closure plug 42.

A control system suitable for actuating a pair of standoff assemblies 10 and an adhesive ejector 33 is shown in FIG. 2 as including a control valve 53 having ports 54, 55, 56 and an actuator 60. In one position, as shown, actuator 60 permits fluid communication between ports 54 and 55 and prevents flow of fluid therebetween to the port 56, and in a second position 5 (not shown) the actuator permits fluid flow between ports 55 and 56 and prevents communication therebetween to the port 54. Fluid lines 61 and 62 are connected respectively to ports 54 and 55 of the control valve 53.

A source of high pressure fluid such as, for example, a carbon dioxide bottle 64 is provided with an actuating device shown as a lever 65, for supplying fluid pressure through a line 66 which divides into line 61 leading to the control valve 53 and line 45 leading to the adhesive ejector 33 as hereinbefore described. The other line 48 connected to the adhesive ejector 33 provides fluid communication between the leg 47 of the ejector closure plug 42 and a cylinder forming part of the control valve 53 and housing the actuator piston 60.

A fluid flow path between the piston side of the standoff assemblies and the control valve 53 is provided by lines 63 leading from fluid couplings 70 in the end closure plugs 22 of the standoff assemblies to the line 62 connected with the port 55 of the control valve.

In use, the object 11 housing the aforedescribed apparatus is placed against the second magnetic object to which it is to be attached and the lever 65 is actuated where upon the lines 63 to one side of the pistons 14 of the standoff assemblies 10 are filled with fluid from the supply 64 via lines 66 and 61, ports 54 and 55 of control valve 53, and line 62. Pressure is applied thereby to pistons 14 forcing longitudinal displacement thereof within the bores 15 of blocks 12, and thereby pushing magnets 23 outward against the second object to magnetically attach the first object to the second object.

When the magnets are outwardly displaced, spring-loaded pins 31 are urged into slots 32. Further movement of the magnets is prevented when the pins 31 are engaged by the shoulder 18 formed on the piston rods 17 by the slots 32. Appropriately, the dimensions of the essential parts comprising the standoff assemblies 10 are prescribed so as to provide a predetermined gap between the two objects when the magnets 23 are fully displaced, which may be on the order of, for example, one-sixteenth of an inch.

Simultaneously, pressure buildup on the piston 35 via fluid communicated thereto from supply 64 through lines 66 and 45 is transmitted through the adhesive 41 in the ejector assembly 33 to the diaphragm 38, causing the diaphragm to rupture. The piston 35 is designed to require greater pressure for actuation than pistons 14 of the standoff assemblies so that it will be actuated after the magnets have been displaced.

When the diaphragm 38 ruptures, the adhesive 41 is squeezed out through bore 40 in the coupler 39 so as to be disposed upon the second object and to substantially fill the gap between the two objects.

After the piston 35 completes its stroke, fluid is permitted to pass from the cavity 44 in the ejector 33, through the leg 47 of the closure 42 and into line 48. Fluid pressure is then applied to the actuator piston 60 switching the control valve 53 to a second, non-illustrated position wherein the pressure in lines 62 is relieved through ports 55 and 56 of the control valve.

The pistons 14 in standoff assemblies 10 are now retracted under the force of springs 21. The pin 31 of each assembly 10 is engaged this time by the shoulder 29 on piston rod 17 formed between slot 32 and channel 30 and thereby permits the magnet 23 of each standoff assembly to withdraw only to a position flush with the surface of the object being attached to the magnetic object. This withdrawal action of the magnets 23 causes the first object to be pulled hard against the second object with the adhesive sandwiched therebetween as the adhesive is permitted to harden.

The particular adhesive to be used in the adhesive ejector does not form a part of this invention, but it is to be understood that the selection of an adhesive is dependent upon the nature of the operation to which the invention is applied. Use of the invention for underwater recovery, for example, would obviously dictate that an adhesive exhibiting good bonding characteristics when in contact with water such as,

for example, a polyester resin adhesive be used. Any adhesive, however, suitable for the environment in which the invention is being used would be acceptable.

bviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed and desired to be secured by Letters Patent of the United States is:

1. An apparatus adhesively connectable to a second object wherein said second object is formed of a ferromagnetic material comprising:

a first object having an extended surface;

means for at least temporarily magnetically attaching said first object to said second object and spacing said second object from said surface of said first object by a predetermined gap;

means for applying an adhesive in said gap while said objects are magnetically attached; and

first means for moving said second object from said spaced position toward said extended surface.

2. Apparatus according to claim 1 wherein said magnetic attaching and spacing means comprises at least one magnet mounted in said first object and movably disposed therein,

second means for moving said magnet beyond the surface of said first object a distance equal to said predetermined gap, and

wherein said first moving means comprises means for retracting said magnet to at least a flush position with said surface.

3. Apparatus according to claim 2 wherein said second magnet moving means comprises a cylinder within said first object,

a piston slidably disposed in said cylinder and having said magnet secured thereto, and

fluid pressure means connected to said cylinder for moving said piston and said magnet.

4. Apparatus according to claim 3 wherein said retracting means comprises fluid pressure relieving means for removing pressure from said piston after said adhesive has been applied, and

a coil spring disposed within said cylinder for urging said piston to withdraw within said first object.

5. Apparatus according to claim 4 wherein said adhesive application means comprises a cylinder adapted to be filled with said adhesive,

an aperture in one end of said cylinder and open to the outside of said first object on the surface thereof to be attached to said second object,

a diaphragm mounted within said cylinder and normally closing said aperture,

piston means movably disposed in said cylinder, and

fluid pressure means connected to the other end of said cylinder for moving said piston to compress said adhesive until said diaphragm ruptures and then to apply adhesive through said aperture to the gap between said first and second objects.

6. Apparatus according to claim 5 wherein said magnetic attaching means comprises at least one magnet mounted in said first object and movably disposed therein,

second means for moving said magnet beyond the surface of said first object a distance equal to said predetermined gap, and

wherein said first moving means includes means for retracting said magnet to a position within said first object and at least flush with the surface thereof.

7. Apparatus according to claim 6 and further including means responsive to the movement of said piston to a predetermined point in said cylinder adjacent said one end thereof for actuating said magnet retracting means. 

1. An apparatus adhesively connectable to a second object wherein said second object is formed of a ferromagnetic material comprising: a first object having an extended surface; means for at least temporarily magnetically attaching said first object to said second object and spacing said second object from said surface of said first object by a predetermined gap; means for applying an adhesive in said gap while said objects are magnetically attached; and first means for moving said second object from said spaced position toward said extended surface.
 2. Apparatus according to claim 1 wherein said magnetic attaching and spacing means comprises at least one magnet mounted in said first object and movably disposed therein, second means for moving said magnet beyond the surface of said first object a distance equal to said predetermined gap, and wherein said first moving means comprises means for retracting said magnet to at least a flush position with said surface.
 3. Apparatus according to claim 2 wherein said second magnet moving means comprises a cylinder within said first object, a piston slidably disposed in said cylinder and having said magnet secured thereto, and fluid pressure means connected to said cylinder for moving said piston and said magnet.
 4. Apparatus according to claim 3 wherein said retracting means comprises fluid pressure relieving means for removing pressure from said piston after said adhesive has been applied, and a coil spring disposed within said cylinder for urging said piston to withdraw within said first object.
 5. Apparatus according to claim 4 wherein said adhesive application means comprises a cylinder adapted to be filled with said adhesive, an aperture in one end of said cylinder and open to the outside of said first object on the surface thereof to be attached to said second object, a diaphragm mounted within said cylinder and normally closing said aperture, piston means movably disposed in said cylinder, and fluid pressure means connected to the other end of said cylinder for moving said piston to compress said adhesive until said diaphragm ruptures and then to apply adhesive through said aperture to the gap between said first and second objects.
 6. Apparatus according to claim 5 wherein said magnetic attaching means comprises at least one magnet mounted in said first object and movably disposed therein, second means for moving said magnet beyond the sUrface of said first object a distance equal to said predetermined gap, and wherein said first moving means includes means for retracting said magnet to a position within said first object and at least flush with the surface thereof.
 7. Apparatus according to claim 6 and further including means responsive to the movement of said piston to a predetermined point in said cylinder adjacent said one end thereof for actuating said magnet retracting means. 